Such an assembly is, for example, known from WO 2011/113454.
With such an assembly it is possible to carry out so-called “volumetric metering,” in which by knowing the thermodynamic conditions prevailing in the chamber before and after injection of gas (pressure, temperature), it is possible to know the mass delivered at the release unit.
In the volumetric metering method, the admission valve is first opened, while maintaining the metering valve closed to fill the chamber with the gas from the supply device.
Once the chamber is filled, the admission valve is closed and the metering valve is opened. The gas escapes from the chamber and flows as far as the release unit.
Such an assembly allows metering of the gas flow with high accuracy for low flow rates. Indeed, the calculation of the injected mass is independent of the corresponding opening durations of the valves and of the transient phases.
On the other hand, such an assembly is not well adapted for providing a high gas flow rate. This flow rate is actually limited by the opening and closing duration of the valves, and by the duration required for filling and emptying the chamber.
In this context, the invention aims at proposing a supply assembly which is well adapted for a more extended gas flow rate range.